This invention is concerned with the provision in the end closure of a bag of a valve sleeve comprising a length of flexible plastic tubing, such as polyethylene tubing, and a kraft reinforcing strip secured together, both forming a means for insertion of a filling tube into the end closure to fill the bag. Use of such tubing in a valve sleeve for a valved bag is desirable, because being limp, the tubing is readily adapted to be pressed flat to seal itself. However, use of the limp tubing per se presents problems in the manufacture of the bag, for the limp tubing is difficult to handle in high speed bag making machinery. Also, when such limp tubing is used in a valve sleeve, it offers little resistance to crimping within the closure when it is sealed, which may tend to bulge the sleeve open and prevent it from becoming tightly flattened, thereby allowing leakage through the sleeve and out of the closure.
Among the objects of this invention is the provision of a valve sleeve in a valved bag, which does not crimp or otherwise not become tightly sealed after filling of the bag through the valve sleeve.